Abrading-machine.



R. C. ROBERTS.

ABBADING MACHINE.

APPLICATION FILED FEB. 12. I917- 1 %%7,152. Patented Nov. 20, 1917. I 3 SHEETS$HEET I.

if. 6 EaZerZa R. 0. ROBERTS.

ABRADLNG MACHINE. APPLICATION. EILED FEB. 12, 1917.

1,247,152. Patented Nov, 20, 1917.

' v if We ROSCOE C. ROBERTS, 0F PEN ABGYL, PENNSYLVANIA.

ABRADING-MACHINE.

Specification of Letters Patent.

Patented Nov. 20, 1917.

Application filed February 12, 1917. Serial No. 148,168.

tain new and useful Improvements in Abrading-Machines; and I do declare the following to be a full, clear, and exact description of the invention such as will enable others skilled in the art to WhlCh 1t appertains to make and use the same. My invention has for its obJect to provide a comparatively simple and lnexpenslve yet an efficient machine for abradmg purposes, such as finishing slate blackboards, slabs and the like. t

With the foregoing general Ob]80t 1n view, the invention resides in the novel features of construction and unique combinations of parts to be hereinafter fully described and claimed, the descriptive matter being supplemented by the accompanying drawings which constitute a part of this application and in which,

Figure 1 is a side-elevation of the 1mproved machine; 7

Fig. 2 is a top plan now thereof;

Fig. 3 is an end elevation partly in section- Fig. 4 is an enlarged vertical section through one of the abrading tools showing more particularly the attachment thereof to its operating shaft; and

Fig. 5 is a detail vertical section on the plane of the line 5-5 of Fig. 4.

In the drawings above briefly described the numerals 1 have reference to a pair of suitably shaped parallel tracks extending horizontally and connected at their ends by transverse bars 2 having supporting legs 3. A work supporting carriage 4 is slidably mounted on the tracks 1 and preferably includes a cast metal frame and wooden slats 5 secured thereto.

The carria e 4 carries a central nut 6 of any suitable ormation which receives therein a longitudinal feed screw 7, said screw having on one end a beveled gear 8 meshing with a pinion 9 on a transverse shaft 10, the outer end of said shaft being equipped with a pair of loose pulleys 11 and a fixed pulley 12 interposed between them, these pulleys cotiperating with a pair of belts 13 and 14, one of which is crossed, a suitable belt shifter 15 being provided for moving either which the belt travels.

one of said belts onto the fixed pulley 12 and simultaneously shifting the other belt onto one of the loose pulleys 11. Both belts 13 and 14 pass around a pulley 16 on the main drive shaft 17 of themachine, which shaft is in turn driven by a pulley 18 around By this arrangement of parts it will be obvious that the screws 7'may be rotated in either direction a for moving the carriage 7 alongthe tracks 1 as required.

The drive shaft 17 extends transversel of the machine and is rotatably mounte in bearings 19 carried by the upper ends of a pair of vertical standards 20 which rise rigidly from the tracks 1, being secured thereto in any. preferred manner midway the ends thereof. Extending between the standards 20 is an upper bar 21 and a lower bar 22 both of which are disposed horizontally and carry bearings 23 in which a plurality of vertical shafts 24 are rotatably and slidably mounted, the upper ends of all of said shafts being provided with intermeshing spur gears 25 through which they slide. The central gear 25 is provided with a beveled gear 26 meshing with a similar gear 27 on the drive shaft 17 so that all the shafts 24 will be driven at a uniform speed and the movement thereof will be synchronized.

Between their ends the shafts 24 are provided with collars 28 which rest rotatably on a horizontal transverse lift bar 29 through which all of said shafts pass, the

ends of said bar being received in vertical slots 30 formed in the standards 20. One

end of bar 29 has a nut 31 in which a vertical screw 32 is threaded, said screw being rotatably mounted in suitable bearings 33 carried by one of the standards 20 and having on its upper end a hand wheel or the like 34 by means of which it may be rotated.

' A link 35 depends from the bar 29 adjacent on both ends of the bar 29, this movement serving to raise all of the shafts 24 to elevate the abraiding tools 40 above the work.

Rotation of the screw 32 in the opposite direction will permit said tools to lower by gravity to perform their functions when the machine is set in operation, and as the tools in question operate upon the slate or the like, the dust will preferably be carried ofl' through a suitable hood 41.

Each tool 40 includes a rectangular block 42 of suitable composition, the upper end of said block being cemented in a socket l3 in the lower side of a comparatively flat head a l, said head having a pair of opposed side flanges l5 between which a pivot bolt 46 passes. The headed, directly beneath the bolt 16, is formed with a channel 47 which,

in transverse section, is formed on an are described around a center located a considerable distance above said bolt. This channel receives loosely therein an elongated rocker 48 which, in transverse section, is formed on an arc of less radius than that of the groove 47, so that the edges of said rocker will be spaced from the Wall of chanrigidly from the lower ends of the shafts 24- at right angles thereto, movement of said eyes, after once adjusted, being prevented by the set screws 50.

The arrangement of parts just described mounts the tools l0 eccentrically on the shafts 2d and said tools are Or such size as to cause each of the same to overlap the area operated on by the adjacent tool. The entire upper surface of the'work will thus be efitectively finished as the several tools are operated while feeding the carriage 5 along the tracks Although the operation of the machine will probably be understood from the fore going, it may be briefly explained as fol-- lows: The work is laid on the carriage land it necessary clamped in place by any suitable means, the tools 40 being then elevated. They are now lowered by means of the screw 34 and the shaft 17 is set in motion. This drives the shafts 24- which in turn movethe tools 40 over the work, the path of eachtool overlapping the path of its companion tools. In the meantime the carriage is fed along the tracks l by the screw 2' and when required may be reversed by proper manipulation of the belt shihter l5.

@n account of the simplicity, ease of opernarrate ation and efliciency of the construction as vention as claimed, numerous minor changes, may be made without sacrificing the P1111011 pal advantages.

ll claim 1. An abrading machine comprising apair of spaced parallel horizontal tracks, a flat carriage movable along said tracks for supporting the work, a pair of rigid standards rising from said tracks, upper and lower rigid horizontal bars extending between and supported by said standards, each bar having a plurality of bearings, a plurality of vertical shafts rotatably mounted in said bearings, intermeshing spur gears of uniform size slidably keyed on the upper ends or said shafts and resting on the *ppermost bar, a beveled gear for one 01", said spur gears, a second beveled gear meshing with said first named gear, a horizontal drive shaft upon which said second vbeveled gear is carried, bearings for said shaft carried by the upper ends or said standards, the intermediate portions of the latter having vertical slots, a third horizontal bar arranged between the aforesaid bars and having its ends received in said slots, collars on said Vertical shafts resting on said third bar, a nut carried by one end or this bar, a screw .rotatably mounted on one of the standards and threaded through said nut, a shaft extending below the aforesaid tracks and having cranks on its opposite ends extending in the same direction, and links rising from said cranks and connected. to the opposite ends of said third bar.

2. An abrading machine comprising a horizontal work support, a, frame rising therefrom, a plurality of vertical shafts r0- tatably and slidably mounted in said name,

the lower ends of said shafts having abrading tools, means for drivingsaidshaits, a horizontal bar through which said shafts pass rotatably the ends of said bar extend ing through vertical slots in theside or the trains, collars'on the shafts resting on said bar, means for adjustingone end of said bar vertically, a link depending from said end, a transverse rock shat't adjacent the work support and having a crank arm to which said link is connected, another crank arm on said rock shaft extending in the same direction as the first named arm, and an additional link rising from said second crank arm and connected to the end of said bar remote from said raising means,

3. An abrading machine comprising a driven shaft, a rigid arm extending laterally from one end thereof, a rocker carried by said arm and having its lower side curved on a comparatively short radius, an abrad- Hill lid

emme ing tool beneath said rocker heving a greove receiving the same, the bottom of said; groove being curve& on a larger redius than said lower side of the rocker, and; apivot connecting the rocker and tool and passing through the former below the center around which its curve lower sMe is described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnessee ROSCOE (L ROBERTS Witnesses:

C. E. SAUERWINE, C. M. SMITH. v 

